HEIDENHAIN TNC 620 (340 56x-02) - Manual (Page 232)

232 Programming: Q Parameters
8.5 Cir
c
le Calculations
8.5 Circle Calculations
Application
The TNC can use the functions for calculating circles to calculate the
circle center and the circle radius from three or four given points on the
circle. The calculation is more accurate if four points are used.
Application: These functions can be used if you wish to determine the
location and size of a hole or a pitch circle using the programmable
probing function.
The coordinate pairs of three points on a circle must be saved in Q30
and the following five parameters—in this case, up to Q35.
The TNC then saves the circle center of the reference axis (X if spindle
axis is Z) in parameter Q20, the circle center in the minor axis (Y if
spindle axis is Z) in parameter Q21, and the circle radius in parameter
Q22.
The coordinate pairs of four points on a circle must be saved in Q30
and the following seven parameters—in this case, up to Q37.
The TNC then saves the circle center of the reference axis (X if spindle
axis is Z) in parameter Q20, the circle center in the minor axis (Y if
spindle axis is Z) in parameter Q21, and the circle radius in parameter
Q22.
Function Soft key
FN 23: Determining the CIRCLE DATA from three
points
Example: FN 23: Q20 = CDATA Q30
Function Soft key
FN 24: Determining the CIRCLE DATA from four
points
Example: FN 24: Q20 = CDATA Q30
Note that FN 23 and FN 24 automatically overwrite the
resulting parameter and the two following parameters.